Local and remote control system for circuit breakers



Patented Dec. 16, 1947 LOCAL AND REMOTE CONTROL SYSTEM FOR CIRCUIT BREAKERS Herman B. Wortman, Pittsburgh -Pa assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation oflPennsylvania Application September 19, 1944, Serial No. 554,785

My invention relates, generally, to control systems and has reference in particular to circuit breaker control systems.

Generally stated, it is an object of my invention to provide a circuit breaker control system which is simple and inexpensive to manufacture and is easy to operate.

More specifically, it is an object of my invention to provide for complete local control of a circuit breaker and to provide, in addition, for remote operation of the circuit breaker at the dis- :retion of an operator at the circuit breaker locaion.

It is also an object of my invention to provide for selective operation of a circuit breaker either locally or remotely without requiring a separate transfer switch or a circuit breaker interlock switch.

Another object of my invention is to provide for using a single manual control switch at a circuit breaker location for operating the circuit breaker and for determining whether or not the circuit breaker may be controlled from a remote point:

Other objects will in part be obvious, and will in part be explained hereinafter.

In practicing my invention a manual control switch is provided at a circuit breaker location for controlling both local and remote operation of the circuit breaker. In one position the control switch provides an energizing circuit for the circuit breaker trip means, in another position it provides an energizing circuit for the closing means, and in a third position it sets up control circuits for the trip and closing means so that they may be selectively controlled by a remote control switch.

For a more complete understanding of the nature and objects of my invention reference may be made to the followin detailed description which may be read in connection with the accompanying drawing, in which the single figure is a diagrammatic view of a circuit breaker control system embodying the invention in one of its forms.

Referring to the drawing the reference numeral l may denote, generally, a circuit breaker for effecting connection of a pair of conductors II to an associated pair of conductors i2 through main contact members We and Nib for controlling the flow of electrical energy therebetween, Energization of the circuit breaker operating winding [4 may be controlled in any suitable manner such as by means of a circuit breaker switch [5 having an operating winding l6 and a cut-off relay l8 having an operating winding IS. The circuit breaker 5 Claims. (Cl. 175-294) maybe retained in the closed position by latch means 20 having associated therewitha trip winding 2| for releasing the latch means to open the circuit breaker.

In order to provide for controlling the operation of the circuit breaker l9, means such as the control switch 22 may be provided adjacent the circuit breaker location. The control switch 22 may, for example, be of the drum type having movable contact members 24 and 25 for effecting connection of the circuit breaker switch I5 and the trip winding 2| in close and trip operating positions of the switch, respectively, to a suitable source of control voltage which may be represented by the conductors 21 and 28. The switch 22 may be of the stay put type which remains in any position to which it is operated until it is operated to another position.

With a view to providing for selectively controlling the circuit breaker l0 either directly from the circuit breaker location or from a remote point additional contact members 29 and 30 may be provided on the control switch 22 for providing energizing circuits when the switch is in the remote. position for the circuit breaker switch I5 and the trip winding 2| in conjunction with a remote control switch 32. The control switch 32 may be of the pushbutton type or may also be of the drum type as shown, having a contact member 33 for connecting the circuit breaker switch 15 to the control conductors 21 and 28 in the close position and a contact member 34 for connecting the trip winding 2| to the control conductors in the "trip position.

With the circuit breaker in the closed position as shown, the local control switch 22 may be operated to the trip position so as to provide an encrgizing'circuit for the trip winding 2! from the control conductor 21 through conductor 36, through auxiliary contact members lilc of the circuit breaker, trip Winding 2|, conductor 31, contact member 25 of the local control switch 22, and conductor 38 to the control conductor 28. The latch means 20 is thereby released opening the circuit breaker. With the local control switch 22 remaining in the "trip position the operator may'safely work on the circuit breaker since it is impossible for the circuit breaker to be closed by means of the remote control switch as the closing circuit therefrom is interrupted by reason of contact member 29 of the local control switch 22'being in the open position.

The circuit breaker may be readily closed by the operator at the circuit breaker location by operating the local control switch 22 to the "close position. An energizing circuit will thereby be provided for the operating winding l6 of the circuit breaker switch I from the control conductor 2'! through conductor 36, conductor 39, contact members I 8b of the cut-oil relay l8, operating winding [6, conductor 40, contact member 24 of the local control switch 22, and conductor 38 to the control conductor 28. The control switch I5 closes, completing an energizing circuit for the operating winding 1 4 of the circuit breaker through contact members I5a. The circuit breaker IE1 closes and provides an energizing circuit for the operating winding I9 of the cut-oii relay l8 through contact members Hid. The cut-off relay then operates to disconnect the operating winding l6 of the circuit breaker switch from the control conductors by opening contact members lBb so as to deenergize the operating winding [4 of the circuit breaker in the well known manner. A holding circuit for the cut-off relay is provided through contact members I8a. With the local control switch 22 remaining in the close position, operation of the circuit breaker from the remote location by means of the remote control switch 32 is again prevented, since the l remote tripping circuit is interrupted by reason of contact member 30 of the local control switch 22 being in the open position,

Whenever the operator is through working on the circuit breaker or whenever he desires to return the circuit breaker to the control of the remote control switch 32, the local control switch 22 may be operated to the remote position. In this position the circuit breaker may be either closed or tripped depending upon its operating position, directly under the control of the remote control switch 32 through obvious operating circuits established through the conductors 4| and 42, and contact members 29 and 30 of the local control switch, respectively.

Suitable signal means such as the red and green lamps 43, 44 may be provided in conjunction with the local control switch for indicating the operating position of the circuit breaker.

Means such as the red and green lamps 46 and 41, respectively, may be provided in conjunction with the remote control switch 32 for likewise effecting indication of the operating position of the circuit breaker.

From the above description and the accompanying drawing it will be apparent that I have provided in a simple and effective manner for selectively controlling a circuit breaker from local and remote locations. Operation of the circuit breaker is always directly under the control of the local operator. In this manner the local operator may always be sure of the operating position of the breaker and may safely work on it whenever he has tripped the circuit breaker from the circuit breaker location, without the danger of having it inadvertently closed from the remote location while he is working on or about it.

Since certain changes may be made in the above description and difierent embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all of the matter contained in the above description and shown in the accompanying drawing shall be considered as illustrative and not in a limiting sense.

I claim as my invention:

1. In a control system for a circuit breaker having trip and closing means, circuit means including a remote control switch operable to different positions to provide diiferent circuits for selectively energizing the trip and closing means, and additional circuit means including a local control switch operable to diiferent positions to provide operating circuits for selectively energizing the tripping or closing means or setting up an operating circuit for the remote control switch.

2. For use with a circuit breaker having trip means and closing means, a local control switch operable to diiferent positions and circuit means connected therewith to provide circuits to selectively energize the trip or closing means or set up remote energizing circuits for said means, and a remote control switch so connected as to be selectively operable to complete one or the other of the remote energizing circuits when the local control switch is operated to set up the remote energizing circuits.

3. In a control system for a circuit breaker having a closing winding and a trip winding, switch means operable to provide a circuit to effect energization of the closing winding from a source of electrical energy, a local control switch operable to different positions to provide diiierent circuits to effect energization of the trip winding, effect energization of the switch means, or set up remote control circuits for energizing the trip winding or switch means, respectively, and a remote control switch selectively operable to diiferent positions for providing circuits to efiect energization of either the trip winding or the switch means over one or another of the remote control circuits.

4. The combination with trip means and closing means for a circuit breaker, of circuit means including a local control switch having contact members operable to different positions for connecting either the trip means or the closing means to a source of electrical energy or connecting them to remote control conductors in difierent ones of the operating positions, and a remote control switch connected to the remote control conductors operable to different positions connected to selectively energize the trip and closing means.

5. A control system for a circuit breaker having an operating winding comprising trip means, a remote control switch operable to different positions connected to set up control circuits to effect energization of the operating winding or the trip means, and a local control switch operable to difierent positions connected to effect energization of the operating winding or the trip means or to complete the control circuits set up by the remote control switch.

HERMAN B. WORTMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

